donut snapshot
diff --git a/libs/utils/file_backup_helper.cpp b/libs/utils/file_backup_helper.cpp
deleted file mode 100644
index 453084a..0000000
--- a/libs/utils/file_backup_helper.cpp
+++ /dev/null
@@ -1,685 +0,0 @@
-#define LOG_TAG "file_backup_helper"
-
-#include <utils/backup_helpers.h>
-
-#include <utils/KeyedVector.h>
-#include <utils/ByteOrder.h>
-#include <utils/String8.h>
-
-#include <errno.h>
-#include <sys/types.h>
-#include <sys/uio.h>
-#include <sys/stat.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <utime.h>
-#include <fcntl.h>
-#include <zlib.h>
-
-#include <cutils/log.h>
-
-using namespace android;
-
-#define MAGIC0 0x70616e53 // Snap
-#define MAGIC1 0x656c6946 // File
-
-#define LOGP(x...) LOGD(x)
-//#define LOGP(x...) printf(x)
-
-struct SnapshotHeader {
-    int magic0;
-    int fileCount;
-    int magic1;
-    int totalSize;
-};
-
-struct FileState {
-    int modTime_sec;
-    int modTime_nsec;
-    int size;
-    int crc32;
-    int nameLen;
-};
-
-const static int ROUND_UP[4] = { 0, 3, 2, 1 };
-
-static inline int
-round_up(int n)
-{
-    return n + ROUND_UP[n % 4];
-}
-
-static int
-read_snapshot_file(int fd, KeyedVector<String8,FileState>* snapshot)
-{
-    int bytesRead = 0;
-    int amt;
-    SnapshotHeader header;
-
-    amt = read(fd, &header, sizeof(header));
-    if (amt != sizeof(header)) {
-        return errno;
-    }
-    bytesRead += amt;
-
-    if (header.magic0 != MAGIC0 || header.magic1 != MAGIC1) {
-        LOGW("read_snapshot_file header.magic0=0x%08x magic1=0x%08x", header.magic0, header.magic1);
-        return 1;
-    }
-
-    for (int i=0; i<header.fileCount; i++) {
-        FileState file;
-        char filenameBuf[128];
-
-        amt = read(fd, &file, sizeof(file));
-        if (amt != sizeof(file)) {
-            LOGW("read_snapshot_file FileState truncated/error with read at %d bytes\n", bytesRead);
-            return 1;
-        }
-        bytesRead += amt;
-
-        // filename is not NULL terminated, but it is padded
-        int nameBufSize = round_up(file.nameLen);
-        char* filename = nameBufSize <= (int)sizeof(filenameBuf)
-                ? filenameBuf
-                : (char*)malloc(nameBufSize);
-        amt = read(fd, filename, nameBufSize);
-        if (amt == nameBufSize) {
-            snapshot->add(String8(filename, file.nameLen), file);
-        }
-        bytesRead += amt;
-        if (filename != filenameBuf) {
-            free(filename);
-        }
-        if (amt != nameBufSize) {
-            LOGW("read_snapshot_file filename truncated/error with read at %d bytes\n", bytesRead);
-            return 1;
-        }
-    }
-
-    if (header.totalSize != bytesRead) {
-        LOGW("read_snapshot_file length mismatch: header.totalSize=%d bytesRead=%d\n",
-                header.totalSize, bytesRead);
-        return 1;
-    }
-
-    return 0;
-}
-
-static int
-write_snapshot_file(int fd, const KeyedVector<String8,FileState>& snapshot)
-{
-    int bytesWritten = sizeof(SnapshotHeader);
-    // preflight size
-    const int N = snapshot.size();
-    for (int i=0; i<N; i++) {
-        const String8& name = snapshot.keyAt(i);
-        bytesWritten += sizeof(FileState) + round_up(name.length());
-    }
-
-    int amt;
-    SnapshotHeader header = { MAGIC0, N, MAGIC1, bytesWritten };
-
-    amt = write(fd, &header, sizeof(header));
-    if (amt != sizeof(header)) {
-        LOGW("write_snapshot_file error writing header %s", strerror(errno));
-        return errno;
-    }
-
-    for (int i=0; i<header.fileCount; i++) {
-        const String8& name = snapshot.keyAt(i);
-        FileState file = snapshot.valueAt(i);
-        int nameLen = file.nameLen = name.length();
-
-        amt = write(fd, &file, sizeof(file));
-        if (amt != sizeof(file)) {
-            LOGW("write_snapshot_file error writing header %s", strerror(errno));
-            return 1;
-        }
-
-        // filename is not NULL terminated, but it is padded
-        amt = write(fd, name.string(), nameLen);
-        if (amt != nameLen) {
-            LOGW("write_snapshot_file error writing filename %s", strerror(errno));
-            return 1;
-        }
-        int paddingLen = ROUND_UP[nameLen % 4];
-        if (paddingLen != 0) {
-            int padding = 0xabababab;
-            amt = write(fd, &padding, paddingLen);
-            if (amt != paddingLen) {
-                LOGW("write_snapshot_file error writing %d bytes of filename padding %s",
-                        paddingLen, strerror(errno));
-                return 1;
-            }
-        }
-    }
-
-    return 0;
-}
-
-static int
-write_delete_file(const String8& key)
-{
-    LOGP("write_delete_file %s\n", key.string());
-    return 0;
-}
-
-static int
-write_update_file(const String8& realFilename, const String8& key)
-{
-    LOGP("write_update_file %s (%s)\n", realFilename.string(), key.string());
-    return 0;
-}
-
-static int
-compute_crc32(const String8& filename)
-{
-    const int bufsize = 4*1024;
-    int amt;
-
-    int fd = open(filename.string(), O_RDONLY);
-    if (fd == -1) {
-        return -1;
-    }
-
-    char* buf = (char*)malloc(bufsize);
-    int crc = crc32(0L, Z_NULL, 0);
-
-    while ((amt = read(fd, buf, bufsize)) != 0) {
-        crc = crc32(crc, (Bytef*)buf, amt);
-    }
-
-    close(fd);
-    free(buf);
-
-    return crc;
-}
-
-int
-back_up_files(int oldSnapshotFD, int oldDataStream, int newSnapshotFD,
-        char const* fileBase, char const* const* files, int fileCount)
-{
-    int err;
-    const String8 base(fileBase);
-    KeyedVector<String8,FileState> oldSnapshot;
-    KeyedVector<String8,FileState> newSnapshot;
-
-    if (oldSnapshotFD != -1) {
-        err = read_snapshot_file(oldSnapshotFD, &oldSnapshot);
-        if (err != 0) {
-            // On an error, treat this as a full backup.
-            oldSnapshot.clear();
-        }
-    }
-
-    for (int i=0; i<fileCount; i++) {
-        String8 name(files[i]);
-        FileState s;
-        struct stat st;
-        String8 realFilename(base);
-        realFilename.appendPath(name);
-
-        err = stat(realFilename.string(), &st);
-        if (err != 0) {
-            LOGW("Error stating file %s", realFilename.string());
-            continue;
-        }
-
-        s.modTime_sec = st.st_mtime;
-        s.modTime_nsec = 0; // workaround sim breakage
-        //s.modTime_nsec = st.st_mtime_nsec;
-        s.size = st.st_size;
-        s.crc32 = compute_crc32(realFilename);
-
-        newSnapshot.add(name, s);
-    }
-
-    int n = 0;
-    int N = oldSnapshot.size();
-    int m = 0;
-
-    while (n<N && m<fileCount) {
-        const String8& p = oldSnapshot.keyAt(n);
-        const String8& q = newSnapshot.keyAt(m);
-        int cmp = p.compare(q);
-        if (cmp > 0) {
-            // file added
-            String8 realFilename(base);
-            realFilename.appendPath(q);
-            write_update_file(realFilename, q);
-            m++;
-        }
-        else if (cmp < 0) {
-            // file removed
-            write_delete_file(p);
-            n++;
-        }
-        else {
-            // both files exist, check them
-            String8 realFilename(base);
-            realFilename.appendPath(q);
-            const FileState& f = oldSnapshot.valueAt(n);
-            const FileState& g = newSnapshot.valueAt(m);
-
-            LOGP("%s\n", q.string());
-            LOGP("  new: modTime=%d,%d size=%-3d crc32=0x%08x\n",
-                    f.modTime_sec, f.modTime_nsec, f.size, f.crc32);
-            LOGP("  old: modTime=%d,%d size=%-3d crc32=0x%08x\n",
-                    g.modTime_sec, g.modTime_nsec, g.size, g.crc32);
-            if (f.modTime_sec != g.modTime_sec || f.modTime_nsec != g.modTime_nsec
-                    || f.size != g.size || f.crc32 != g.crc32) {
-                write_update_file(realFilename, p);
-            }
-            n++;
-            m++;
-        }
-    }
-
-    // these were deleted
-    while (n<N) {
-        write_delete_file(oldSnapshot.keyAt(n));
-        n++;
-    }
-
-    // these were added
-    while (m<fileCount) {
-        const String8& q = newSnapshot.keyAt(m);
-        String8 realFilename(base);
-        realFilename.appendPath(q);
-        write_update_file(realFilename, q);
-        m++;
-    }
-
-    err = write_snapshot_file(newSnapshotFD, newSnapshot);
-
-    return 0;
-}
-
-#if TEST_BACKUP_HELPERS
-
-#define SCRATCH_DIR "/data/backup_helper_test/"
-
-static int
-write_text_file(const char* path, const char* data)
-{
-    int amt;
-    int fd;
-    int len;
-
-    fd = creat(path, 0666);
-    if (fd == -1) {
-        fprintf(stderr, "creat %s failed\n", path);
-        return errno;
-    }
-
-    len = strlen(data);
-    amt = write(fd, data, len);
-    if (amt != len) {
-        fprintf(stderr, "error (%s) writing to file %s\n", strerror(errno), path);
-        return errno;
-    }
-
-    close(fd);
-
-    return 0;
-}
-
-static int
-compare_file(const char* path, const unsigned char* data, int len)
-{
-    int fd;
-    int amt;
-
-    fd = open(path, O_RDONLY);
-    if (fd == -1) {
-        fprintf(stderr, "compare_file error (%s) opening %s\n", strerror(errno), path);
-        return errno;
-    }
-
-    unsigned char* contents = (unsigned char*)malloc(len);
-    if (contents == NULL) {
-        fprintf(stderr, "malloc(%d) failed\n", len);
-        return ENOMEM;
-    }
-
-    bool sizesMatch = true;
-    amt = lseek(fd, 0, SEEK_END);
-    if (amt != len) {
-        fprintf(stderr, "compare_file file length should be %d, was %d\n", len, amt);
-        sizesMatch = false;
-    }
-    lseek(fd, 0, SEEK_SET);
-
-    int readLen = amt < len ? amt : len;
-    amt = read(fd, contents, readLen);
-    if (amt != readLen) {
-        fprintf(stderr, "compare_file read expected %d bytes but got %d\n", len, amt);
-    }
-
-    bool contentsMatch = true;
-    for (int i=0; i<readLen; i++) {
-        if (data[i] != contents[i]) {
-            if (contentsMatch) {
-                fprintf(stderr, "compare_file contents are different: (index, expected, actual)\n");
-                contentsMatch = false;
-            }
-            fprintf(stderr, "  [%-2d] %02x %02x\n", i, data[i], contents[i]);
-        }
-    }
-
-    return contentsMatch && sizesMatch ? 0 : 1;
-}
-
-int
-backup_helper_test_empty()
-{
-    int err;
-    int fd;
-    KeyedVector<String8,FileState> snapshot;
-    const char* filename = SCRATCH_DIR "backup_helper_test_empty.snap";
-
-    system("rm -r " SCRATCH_DIR);
-    mkdir(SCRATCH_DIR, 0777);
-
-    // write
-    fd = creat(filename, 0666);
-    if (fd == -1) {
-        fprintf(stderr, "error creating %s\n", filename);
-        return 1;
-    }
-
-    err = write_snapshot_file(fd, snapshot);
-
-    close(fd);
-
-    if (err != 0) {
-        fprintf(stderr, "write_snapshot_file reported error %d (%s)\n", err, strerror(err));
-        return err;
-    }
-
-    static const unsigned char correct_data[] = {
-        0x53, 0x6e, 0x61, 0x70,  0x00, 0x00, 0x00, 0x00,
-        0x46, 0x69, 0x6c, 0x65,  0x10, 0x00, 0x00, 0x00
-    };
-
-    err = compare_file(filename, correct_data, sizeof(correct_data));
-    if (err != 0) {
-        return err;
-    }
-
-    // read
-    fd = open(filename, O_RDONLY);
-    if (fd == -1) {
-        fprintf(stderr, "error opening for read %s\n", filename);
-        return 1;
-    }
-
-    KeyedVector<String8,FileState> readSnapshot;
-    err = read_snapshot_file(fd, &readSnapshot);
-    if (err != 0) {
-        fprintf(stderr, "read_snapshot_file failed %d\n", err);
-        return err;
-    }
-
-    if (readSnapshot.size() != 0) {
-        fprintf(stderr, "readSnapshot should be length 0\n");
-        return 1;
-    }
-
-    return 0;
-}
-
-int
-backup_helper_test_four()
-{
-    int err;
-    int fd;
-    KeyedVector<String8,FileState> snapshot;
-    const char* filename = SCRATCH_DIR "backup_helper_test_four.snap";
-
-    system("rm -r " SCRATCH_DIR);
-    mkdir(SCRATCH_DIR, 0777);
-
-    // write
-    fd = creat(filename, 0666);
-    if (fd == -1) {
-        fprintf(stderr, "error opening %s\n", filename);
-        return 1;
-    }
-
-    String8 filenames[4];
-    FileState states[4];
-
-    states[0].modTime_sec = 0xfedcba98;
-    states[0].modTime_nsec = 0xdeadbeef;
-    states[0].size = 0xababbcbc;
-    states[0].crc32 = 0x12345678;
-    states[0].nameLen = -12;
-    filenames[0] = String8("bytes_of_padding");
-    snapshot.add(filenames[0], states[0]);
-
-    states[1].modTime_sec = 0x93400031;
-    states[1].modTime_nsec = 0xdeadbeef;
-    states[1].size = 0x88557766;
-    states[1].crc32 = 0x22334422;
-    states[1].nameLen = -1;
-    filenames[1] = String8("bytes_of_padding3");
-    snapshot.add(filenames[1], states[1]);
-
-    states[2].modTime_sec = 0x33221144;
-    states[2].modTime_nsec = 0xdeadbeef;
-    states[2].size = 0x11223344;
-    states[2].crc32 = 0x01122334;
-    states[2].nameLen = 0;
-    filenames[2] = String8("bytes_of_padding_2");
-    snapshot.add(filenames[2], states[2]);
-
-    states[3].modTime_sec = 0x33221144;
-    states[3].modTime_nsec = 0xdeadbeef;
-    states[3].size = 0x11223344;
-    states[3].crc32 = 0x01122334;
-    states[3].nameLen = 0;
-    filenames[3] = String8("bytes_of_padding__1");
-    snapshot.add(filenames[3], states[3]);
-
-    err = write_snapshot_file(fd, snapshot);
-
-    close(fd);
-
-    if (err != 0) {
-        fprintf(stderr, "write_snapshot_file reported error %d (%s)\n", err, strerror(err));
-        return err;
-    }
-
-    static const unsigned char correct_data[] = {
-        // header
-        0x53, 0x6e, 0x61, 0x70,  0x04, 0x00, 0x00, 0x00,
-        0x46, 0x69, 0x6c, 0x65,  0xac, 0x00, 0x00, 0x00,
-
-        // bytes_of_padding
-        0x98, 0xba, 0xdc, 0xfe,  0xef, 0xbe, 0xad, 0xde,
-        0xbc, 0xbc, 0xab, 0xab,  0x78, 0x56, 0x34, 0x12,
-        0x10, 0x00, 0x00, 0x00,  0x62, 0x79, 0x74, 0x65,
-        0x73, 0x5f, 0x6f, 0x66,  0x5f, 0x70, 0x61, 0x64,
-        0x64, 0x69, 0x6e, 0x67,
-
-        // bytes_of_padding3
-        0x31, 0x00, 0x40, 0x93,  0xef, 0xbe, 0xad, 0xde,
-        0x66, 0x77, 0x55, 0x88,  0x22, 0x44, 0x33, 0x22,
-        0x11, 0x00, 0x00, 0x00,  0x62, 0x79, 0x74, 0x65,
-        0x73, 0x5f, 0x6f, 0x66,  0x5f, 0x70, 0x61, 0x64,
-        0x64, 0x69, 0x6e, 0x67,  0x33, 0xab, 0xab, 0xab,
-        
-        // bytes of padding2
-        0x44, 0x11, 0x22, 0x33,  0xef, 0xbe, 0xad, 0xde,
-        0x44, 0x33, 0x22, 0x11,  0x34, 0x23, 0x12, 0x01,
-        0x12, 0x00, 0x00, 0x00,  0x62, 0x79, 0x74, 0x65,
-        0x73, 0x5f, 0x6f, 0x66,  0x5f, 0x70, 0x61, 0x64,
-        0x64, 0x69, 0x6e, 0x67,  0x5f, 0x32, 0xab, 0xab,
-        
-        // bytes of padding3
-        0x44, 0x11, 0x22, 0x33,  0xef, 0xbe, 0xad, 0xde,
-        0x44, 0x33, 0x22, 0x11,  0x34, 0x23, 0x12, 0x01,
-        0x13, 0x00, 0x00, 0x00,  0x62, 0x79, 0x74, 0x65,
-        0x73, 0x5f, 0x6f, 0x66,  0x5f, 0x70, 0x61, 0x64,
-        0x64, 0x69, 0x6e, 0x67,  0x5f, 0x5f, 0x31, 0xab
-    };
-
-    err = compare_file(filename, correct_data, sizeof(correct_data));
-    if (err != 0) {
-        return err;
-    }
-    
-    // read
-    fd = open(filename, O_RDONLY);
-    if (fd == -1) {
-        fprintf(stderr, "error opening for read %s\n", filename);
-        return 1;
-    }
-
-
-    KeyedVector<String8,FileState> readSnapshot;
-    err = read_snapshot_file(fd, &readSnapshot);
-    if (err != 0) {
-        fprintf(stderr, "read_snapshot_file failed %d\n", err);
-        return err;
-    }
-
-    if (readSnapshot.size() != 4) {
-        fprintf(stderr, "readSnapshot should be length 4 is %d\n", readSnapshot.size());
-        return 1;
-    }
-
-    bool matched = true;
-    for (size_t i=0; i<readSnapshot.size(); i++) {
-        const String8& name = readSnapshot.keyAt(i);
-        const FileState state = readSnapshot.valueAt(i);
-
-        if (name != filenames[i] || states[i].modTime_sec != state.modTime_sec
-                || states[i].modTime_nsec != state.modTime_nsec
-                || states[i].size != state.size || states[i].crc32 != states[i].crc32) {
-            fprintf(stderr, "state %d expected={%d/%d, 0x%08x, 0x%08x, %3d} '%s'\n"
-                            "          actual={%d/%d, 0x%08x, 0x%08x, %3d} '%s'\n", i,
-                    states[i].modTime_sec, states[i].modTime_nsec, states[i].size, states[i].crc32,
-                    name.length(), filenames[i].string(),
-                    state.modTime_sec, state.modTime_nsec, state.size, state.crc32, state.nameLen,
-                    name.string());
-            matched = false;
-        }
-    }
-    
-    return matched ? 0 : 1;
-}
-
-static int
-get_mod_time(const char* filename, struct timeval times[2])
-{
-    int err;
-    struct stat64 st;
-    err = stat64(filename, &st);
-    if (err != 0) {
-        fprintf(stderr, "stat '%s' failed: %s\n", filename, strerror(errno));
-        return errno;
-    }
-    times[0].tv_sec = st.st_atime;
-    times[0].tv_usec = st.st_atime_nsec / 1000;
-    times[1].tv_sec = st.st_mtime;
-    times[1].tv_usec = st.st_mtime_nsec / 1000;
-    return 0;
-}
-
-int
-backup_helper_test_files()
-{
-    int err;
-    int newSnapshotFD;
-    int oldSnapshotFD;
-
-    system("rm -r " SCRATCH_DIR);
-    mkdir(SCRATCH_DIR, 0777);
-    mkdir(SCRATCH_DIR "data", 0777);
-
-    write_text_file(SCRATCH_DIR "data/b", "b\nbb\n");
-    write_text_file(SCRATCH_DIR "data/c", "c\ncc\n");
-    write_text_file(SCRATCH_DIR "data/d", "d\ndd\n");
-    write_text_file(SCRATCH_DIR "data/e", "e\nee\n");
-    write_text_file(SCRATCH_DIR "data/f", "f\nff\n");
-    write_text_file(SCRATCH_DIR "data/h", "h\nhh\n");
-
-    char const* files_before[] = {
-        "data/b",
-        "data/c",
-        "data/d",
-        "data/e",
-        "data/f"
-    };
-
-    newSnapshotFD = creat(SCRATCH_DIR "before.snap", 0666);
-    if (newSnapshotFD == -1) {
-        fprintf(stderr, "error creating: %s\n", strerror(errno));
-        return errno;
-    }
-
-    err = back_up_files(-1, newSnapshotFD, 0, SCRATCH_DIR, files_before, 5);
-    if (err != 0) {
-        return err;
-    }
-
-    close(newSnapshotFD);
-
-    sleep(3);
-
-    struct timeval d_times[2];
-    struct timeval e_times[2];
-
-    err = get_mod_time(SCRATCH_DIR "data/d", d_times);
-    err |= get_mod_time(SCRATCH_DIR "data/e", e_times);
-    if (err != 0) {
-        return err;
-    }
-
-    write_text_file(SCRATCH_DIR "data/a", "a\naa\n");
-    unlink(SCRATCH_DIR "data/c");
-    write_text_file(SCRATCH_DIR "data/c", "c\ncc\n");
-    write_text_file(SCRATCH_DIR "data/d", "dd\ndd\n");
-    utimes(SCRATCH_DIR "data/d", d_times);
-    write_text_file(SCRATCH_DIR "data/e", "z\nzz\n");
-    utimes(SCRATCH_DIR "data/e", e_times);
-    write_text_file(SCRATCH_DIR "data/g", "g\ngg\n");
-    unlink(SCRATCH_DIR "data/f");
-    
-    char const* files_after[] = {
-        "data/a", // added
-        "data/b", // same
-        "data/c", // different mod time
-        "data/d", // different size (same mod time)
-        "data/e", // different contents (same mod time, same size)
-        "data/g"  // added
-    };
-
-    oldSnapshotFD = open(SCRATCH_DIR "before.snap", O_RDONLY);
-    if (oldSnapshotFD == -1) {
-        fprintf(stderr, "error opening: %s\n", strerror(errno));
-        return errno;
-    }
-
-    newSnapshotFD = creat(SCRATCH_DIR "after.snap", 0666);
-    if (newSnapshotFD == -1) {
-        fprintf(stderr, "error creating: %s\n", strerror(errno));
-        return errno;
-    }
-
-    err = back_up_files(oldSnapshotFD, newSnapshotFD, 0, SCRATCH_DIR, files_after, 6);
-    if (err != 0) {
-        return err;
-    }
-
-    close(oldSnapshotFD);
-    close(newSnapshotFD);
-    
-    return 0;
-}
-
-#endif // TEST_BACKUP_HELPERS